What do these games have in common? Foremost, they are fun for nearly any (reasonably) sized group. In the case of games that have a limited number of pieces, teams are possible, encouraged or (for Pictionary, at least) required.

Secondly, though strategy has a place in some of the above games, their main point is to promote player interaction and entertainment. Smashing the opposition is not the real goal, though this probably has more to do with normal party atmosphere than the games themselves.

Thirdly, packaged party games require very little set up and take down, and the others require almost none.

Sixthly and lastly, several of the above games have time limits on turns. This keeps the game moving toward the conclusion and gives everyone a chance to play.